diff --git a/sql/upgrades/119.sql b/sql/upgrades/119.sql
new file mode 100644
--- /dev/null
+++ b/sql/upgrades/119.sql
@@ -0,0 +1,19 @@
+-- SWH Indexer DB schema upgrade
+-- from_version: 118
+-- to_version: 119
+-- description: metadata tables: add 'mappings' column
+
+insert into dbversion(version, release, description)
+values(119, now(), 'Work In Progress');
+
+alter table revision_metadata
+  add column mappings text array not null default {};
+alter table revision_metadata
+  alter column mappings
+    drop default;
+
+alter table origin_intrinsic_metadata
+  add column mappings text array not null default {};
+alter table origin_intrinsic_metadata
+  alter column mappings
+    drop default;
diff --git a/swh/indexer/metadata.py b/swh/indexer/metadata.py
--- a/swh/indexer/metadata.py
+++ b/swh/indexer/metadata.py
@@ -150,6 +150,7 @@
         result = {
             'id': rev['id'],
             'indexer_configuration_id': self.tool['id'],
+            'mappings': None,
             'translated_metadata': None
         }
 
@@ -158,10 +159,11 @@
             dir_ls = self.storage.directory_ls(root_dir, recursive=False)
             files = [entry for entry in dir_ls if entry['type'] == 'file']
             detected_files = detect_metadata(files)
-            result['translated_metadata'] = self.translate_revision_metadata(
+            (mappings, metadata) = self.translate_revision_metadata(
                 detected_files,
-                log_suffix='revision=%s' % hashutil.hash_to_hex(rev['id'])
-            )
+                log_suffix='revision=%s' % hashutil.hash_to_hex(rev['id']))
+            result['mappings'] = mappings
+            result['translated_metadata'] = metadata
         except Exception as e:
             self.log.exception(
                 'Problem when indexing rev: %r', e)
@@ -194,10 +196,11 @@
               "npm", "authors") to list of sha1
 
         Returns:
-            dict: dict with translated metadata according to the CodeMeta
-            vocabulary
+            (List[str], dict): list of mappings used and dict with
+            translated metadata according to the CodeMeta vocabulary
 
         """
+        used_mappings = [MAPPINGS[context].name for context in detected_files]
         translated_metadata = []
         tool = {
                 'name': 'swh-metadata-translator',
@@ -252,7 +255,7 @@
 
         # transform translated_metadata into min set with swh-metadata-detector
         min_metadata = extract_minimal_metadata_dict(translated_metadata)
-        return min_metadata
+        return (used_mappings, min_metadata)
 
 
 class OriginMetadataIndexer(OriginIndexer):
@@ -287,6 +290,7 @@
             'from_revision': rev_metadata['id'],
             'origin_id': origin['id'],
             'metadata': rev_metadata['translated_metadata'],
+            'mappings': rev_metadata['mappings'],
             'indexer_configuration_id':
                 rev_metadata['indexer_configuration_id'],
         }
diff --git a/swh/indexer/metadata_dictionary.py b/swh/indexer/metadata_dictionary.py
--- a/swh/indexer/metadata_dictionary.py
+++ b/swh/indexer/metadata_dictionary.py
@@ -76,6 +76,13 @@
             self.__class__.__module__,
             self.__class__.__name__))
 
+    @property
+    @abc.abstractmethod
+    def name(self):
+        """A name of this mapping, used as an identifier in the
+        indexer storage."""
+        pass
+
     @classmethod
     @abc.abstractmethod
     def detect_metadata_files(cls, files):
@@ -203,6 +210,7 @@
     """
     dedicated class for NPM (package.json) mapping and translation
     """
+    name = 'npm'
     mapping = CROSSWALK_TABLE['NodeJS']
     filename = b'package.json'
 
@@ -341,6 +349,7 @@
     """
     dedicated class for CodeMeta (codemeta.json) mapping and translation
     """
+    name = 'codemeta'
     filename = b'codemeta.json'
 
     def translate(self, content):
@@ -352,6 +361,7 @@
     """
     dedicated class for Maven (pom.xml) mapping and translation
     """
+    name = 'maven'
     filename = b'pom.xml'
     mapping = CROSSWALK_TABLE['Java (Maven)']
 
@@ -484,6 +494,7 @@
     """Dedicated class for Python's PKG-INFO mapping and translation.
 
     https://www.python.org/dev/peps/pep-0314/"""
+    name = 'pkg-info'
     filename = b'PKG-INFO'
     mapping = {_normalize_pkginfo_key(k): v
                for (k, v) in CROSSWALK_TABLE['Python PKG-INFO'].items()}
@@ -520,11 +531,12 @@
 
 @register_mapping
 class GemspecMapping(DictMapping):
+    name = 'gemspec'
+    mapping = CROSSWALK_TABLE['Ruby Gem']
+
     _re_spec_new = re.compile(r'.*Gem::Specification.new do \|.*\|.*')
     _re_spec_entry = re.compile(r'\s*\w+\.(?P<key>\w+)\s*=\s*(?P<expr>.*)')
 
-    mapping = CROSSWALK_TABLE['Ruby Gem']
-
     @classmethod
     def detect_metadata_files(cls, file_entries):
         for entry in file_entries:
diff --git a/swh/indexer/sql/30-swh-schema.sql b/swh/indexer/sql/30-swh-schema.sql
--- a/swh/indexer/sql/30-swh-schema.sql
+++ b/swh/indexer/sql/30-swh-schema.sql
@@ -14,7 +14,7 @@
 );
 
 insert into dbversion(version, release, description)
-      values(118, now(), 'Work In Progress');
+      values(119, now(), 'Work In Progress');
 -- Computing metadata on sha1's contents
 
 -- a SHA1 checksum (not necessarily originating from Git)
@@ -118,7 +118,8 @@
 create table revision_metadata(
   id                       sha1_git   not null,
   translated_metadata      jsonb      not null,
-  indexer_configuration_id bigint     not null
+  indexer_configuration_id bigint     not null,
+  mappings                 text array not null
 );
 
 comment on table revision_metadata is 'metadata semantically detected and translated in a revision';
@@ -131,7 +132,8 @@
   metadata                  jsonb,
   indexer_configuration_id  bigint     not null,
   from_revision             sha1_git   not null,
-  metadata_tsvector         tsvector
+  metadata_tsvector         tsvector,
+  mappings                  text array not null
 );
 
 comment on table origin_intrinsic_metadata is 'keeps intrinsic metadata for an origin';
diff --git a/swh/indexer/sql/40-swh-func.sql b/swh/indexer/sql/40-swh-func.sql
--- a/swh/indexer/sql/40-swh-func.sql
+++ b/swh/indexer/sql/40-swh-func.sql
@@ -315,15 +315,15 @@
 as $$
 begin
     if conflict_update then
-      insert into revision_metadata (id, translated_metadata, indexer_configuration_id)
-      select id, translated_metadata, indexer_configuration_id
+      insert into revision_metadata (id, translated_metadata, mappings, indexer_configuration_id)
+      select id, translated_metadata, mappings, indexer_configuration_id
     	from tmp_revision_metadata tcm
             on conflict(id, indexer_configuration_id)
                 do update set translated_metadata = excluded.translated_metadata;
 
     else
-        insert into revision_metadata (id, translated_metadata, indexer_configuration_id)
-        select id, translated_metadata, indexer_configuration_id
+        insert into revision_metadata (id, translated_metadata, mappings, indexer_configuration_id)
+        select id, translated_metadata, mappings, indexer_configuration_id
     	from tmp_revision_metadata tcm
             on conflict(id, indexer_configuration_id)
             do nothing;
@@ -410,17 +410,17 @@
 begin
     perform swh_origin_intrinsic_metadata_compute_tsvector();
     if conflict_update then
-      insert into origin_intrinsic_metadata (origin_id, metadata, indexer_configuration_id, from_revision, metadata_tsvector)
+      insert into origin_intrinsic_metadata (origin_id, metadata, indexer_configuration_id, from_revision, metadata_tsvector, mappings)
       select origin_id, metadata, indexer_configuration_id, from_revision,
-             metadata_tsvector
+             metadata_tsvector, mappings
     	from tmp_origin_intrinsic_metadata
             on conflict(origin_id, indexer_configuration_id)
                 do update set metadata = excluded.metadata;
 
     else
-        insert into origin_intrinsic_metadata (origin_id, metadata, indexer_configuration_id, from_revision, metadata_tsvector)
+        insert into origin_intrinsic_metadata (origin_id, metadata, indexer_configuration_id, from_revision, metadata_tsvector, mappings)
         select origin_id, metadata, indexer_configuration_id, from_revision,
-               metadata_tsvector
+               metadata_tsvector, mappings
     	from tmp_origin_intrinsic_metadata
             on conflict(origin_id, indexer_configuration_id)
             do nothing;
diff --git a/swh/indexer/storage/__init__.py b/swh/indexer/storage/__init__.py
--- a/swh/indexer/storage/__init__.py
+++ b/swh/indexer/storage/__init__.py
@@ -586,6 +586,8 @@
                 - **id** (bytes)
                 - **translated_metadata** (str): associated metadata
                 - **tool** (dict): tool used to compute metadata
+                - **mappings** (List[str]): list of mappings used to translate
+                  these metadata
 
         """
         for c in db.revision_metadata_get_from_list(ids, cur):
@@ -604,6 +606,8 @@
                 - **id**: sha1_git of revision
                 - **translated_metadata**: arbitrary dict
                 - **indexer_configuration_id**: tool used to compute metadata
+                - **mappings** (List[str]): list of mappings used to translate
+                  these metadata
 
             conflict_update: Flag to determine if we want to overwrite (true)
               or skip duplicates (false, the default)
@@ -612,7 +616,8 @@
         db.mktemp_revision_metadata(cur)
 
         db.copy_to(metadata, 'tmp_revision_metadata',
-                   ['id', 'translated_metadata', 'indexer_configuration_id'],
+                   ['id', 'translated_metadata', 'mappings',
+                    'indexer_configuration_id'],
                    cur)
         db.revision_metadata_add_from_temp(conflict_update, cur)
 
@@ -630,6 +635,8 @@
                 - **origin_id** (int)
                 - **metadata** (str): associated metadata
                 - **tool** (dict): tool used to compute metadata
+                - **mappings** (List[str]): list of mappings used to translate
+                  these metadata
 
         """
         for c in db.origin_intrinsic_metadata_get_from_list(ids, cur):
@@ -651,6 +658,8 @@
                   these metadata.
                 - **metadata**: arbitrary dict
                 - **indexer_configuration_id**: tool used to compute metadata
+                - **mappings** (List[str]): list of mappings used to translate
+                  these metadata
 
             conflict_update: Flag to determine if we want to overwrite (true)
               or skip duplicates (false, the default)
@@ -660,7 +669,7 @@
 
         db.copy_to(metadata, 'tmp_origin_intrinsic_metadata',
                    ['origin_id', 'metadata', 'indexer_configuration_id',
-                       'from_revision'],
+                    'from_revision', 'mappings'],
                    cur)
         db.origin_intrinsic_metadata_add_from_temp(conflict_update, cur)
 
@@ -680,6 +689,8 @@
                 - **id** (int)
                 - **metadata** (str): associated metadata
                 - **tool** (dict): tool used to compute metadata
+                - **mappings** (List[str]): list of mappings used to translate
+                  these metadata
 
         """
         for c in db.origin_intrinsic_metadata_search_fulltext(
diff --git a/swh/indexer/storage/db.py b/swh/indexer/storage/db.py
--- a/swh/indexer/storage/db.py
+++ b/swh/indexer/storage/db.py
@@ -295,7 +295,8 @@
         yield from self._get_from_list(
             'content_metadata', ids, self.content_metadata_cols, cur=cur)
 
-    revision_metadata_hash_keys = ['id', 'indexer_configuration_id']
+    revision_metadata_hash_keys = [
+        'id', 'indexer_configuration_id']
 
     def revision_metadata_missing_from_list(self, metadata, cur=None):
         """List missing metadata.
@@ -306,7 +307,7 @@
             cur=cur)
 
     revision_metadata_cols = [
-        'id', 'translated_metadata',
+        'id', 'translated_metadata', 'mappings',
         'tool_id', 'tool_name', 'tool_version', 'tool_configuration']
 
     @stored_procedure('swh_mktemp_revision_metadata')
@@ -321,7 +322,7 @@
             'revision_metadata', ids, self.revision_metadata_cols, cur=cur)
 
     origin_intrinsic_metadata_cols = [
-        'origin_id', 'metadata', 'from_revision',
+        'origin_id', 'metadata', 'from_revision', 'mappings',
         'tool_id', 'tool_name', 'tool_version', 'tool_configuration']
 
     origin_intrinsic_metadata_regconfig = 'pg_catalog.simple'
diff --git a/swh/indexer/tests/storage/test_storage.py b/swh/indexer/tests/storage/test_storage.py
--- a/swh/indexer/tests/storage/test_storage.py
+++ b/swh/indexer/tests/storage/test_storage.py
@@ -1217,6 +1217,7 @@
                 'softwareRequirements': None,
                 'identifier': None
             },
+            'mappings': [],
             'indexer_configuration_id': tool_id
         }])
 
@@ -1250,6 +1251,7 @@
                 'softwareRequirements': None,
                 'identifier': None
             },
+            'mappings': ['mapping1', 'mapping2'],
             'indexer_configuration_id': tool_id
         }
 
@@ -1263,9 +1265,11 @@
         expected_metadata = [{
             'id': self.revision_id_2,
             'translated_metadata': metadata_rev['translated_metadata'],
+            'mappings': ['mapping1', 'mapping2'],
             'tool': self.tools['swh-metadata-detector']
         }]
 
+        self.maxDiff = None
         self.assertEqual(actual_metadata, expected_metadata)
 
     def test_revision_metadata_add_drop_duplicate(self):
@@ -1291,6 +1295,7 @@
                 'softwareRequirements': None,
                 'identifier': None
             },
+            'mappings': [],
             'indexer_configuration_id': tool_id,
         }
 
@@ -1304,6 +1309,7 @@
         expected_metadata_v1 = [{
             'id': self.revision_id_1,
             'translated_metadata':  metadata_v1['translated_metadata'],
+            'mappings': [],
             'tool': self.tools['swh-metadata-detector']
         }]
 
@@ -1350,6 +1356,7 @@
                 'softwareRequirements': None,
                 'identifier': None
             },
+            'mappings': [],
             'indexer_configuration_id': tool_id,
         }
 
@@ -1364,6 +1371,7 @@
         expected_metadata_v1 = [{
             'id': self.revision_id_2,
             'translated_metadata':  metadata_v1['translated_metadata'],
+            'mappings': [],
             'tool': self.tools['swh-metadata-detector']
         }]
         self.assertEqual(actual_metadata, expected_metadata_v1)
@@ -1384,6 +1392,7 @@
         expected_metadata_v2 = [{
             'id': self.revision_id_2,
             'translated_metadata': metadata_v2['translated_metadata'],
+            'mappings': [],
             'tool': self.tools['swh-metadata-detector']
         }]
 
@@ -1414,12 +1423,14 @@
         metadata_rev = {
             'id': self.revision_id_2,
             'translated_metadata': metadata,
+            'mappings': ['mapping1'],
             'indexer_configuration_id': tool_id,
         }
         metadata_origin = {
             'origin_id': self.origin_id_1,
             'metadata': metadata,
             'indexer_configuration_id': tool_id,
+            'mappings': ['mapping1'],
             'from_revision': self.revision_id_2,
             }
 
@@ -1436,6 +1447,7 @@
             'metadata': metadata,
             'tool': self.tools['swh-metadata-detector'],
             'from_revision': self.revision_id_2,
+            'mappings': ['mapping1'],
         }]
 
         self.assertEqual(actual_metadata, expected_metadata)
@@ -1464,12 +1476,14 @@
         metadata_rev_v1 = {
             'id': self.revision_id_1,
             'translated_metadata': metadata_v1.copy(),
+            'mappings': [],
             'indexer_configuration_id': tool_id,
         }
         metadata_origin_v1 = {
             'origin_id': self.origin_id_1,
             'metadata': metadata_v1.copy(),
             'indexer_configuration_id': tool_id,
+            'mappings': [],
             'from_revision': self.revision_id_1,
         }
 
@@ -1486,6 +1500,7 @@
             'metadata': metadata_v1,
             'tool': self.tools['swh-metadata-detector'],
             'from_revision': self.revision_id_1,
+            'mappings': [],
         }]
 
         self.assertEqual(actual_metadata, expected_metadata_v1)
@@ -1535,12 +1550,14 @@
         metadata_rev_v1 = {
             'id': self.revision_id_2,
             'translated_metadata': metadata_v1,
+            'mappings': [],
             'indexer_configuration_id': tool_id,
         }
         metadata_origin_v1 = {
             'origin_id': self.origin_id_1,
             'metadata': metadata_v1.copy(),
             'indexer_configuration_id': tool_id,
+            'mappings': [],
             'from_revision': self.revision_id_2,
         }
 
@@ -1558,6 +1575,7 @@
             'metadata': metadata_v1,
             'tool': self.tools['swh-metadata-detector'],
             'from_revision': self.revision_id_2,
+            'mappings': [],
         }]
         self.assertEqual(actual_metadata, expected_metadata_v1)
 
@@ -1585,6 +1603,7 @@
             'metadata': metadata_v2,
             'tool': self.tools['swh-metadata-detector'],
             'from_revision': self.revision_id_2,
+            'mappings': [],
         }]
 
         # metadata did change as the v2 was used to overwrite v1
@@ -1600,11 +1619,13 @@
         metadata1_rev = {
             'id': self.revision_id_1,
             'translated_metadata': metadata1,
+            'mappings': [],
             'indexer_configuration_id': tool_id,
         }
         metadata1_origin = {
             'origin_id': self.origin_id_1,
             'metadata': metadata1,
+            'mappings': [],
             'indexer_configuration_id': tool_id,
             'from_revision': self.revision_id_1,
         }
@@ -1614,11 +1635,13 @@
         metadata2_rev = {
             'id': self.revision_id_2,
             'translated_metadata': metadata2,
+            'mappings': [],
             'indexer_configuration_id': tool_id,
         }
         metadata2_origin = {
             'origin_id': self.origin_id_2,
             'metadata': metadata2,
+            'mappings': [],
             'indexer_configuration_id': tool_id,
             'from_revision': self.revision_id_2,
         }
@@ -1662,11 +1685,13 @@
         metadata1_rev = {
             'id': self.revision_id_1,
             'translated_metadata': metadata1,
+            'mappings': [],
             'indexer_configuration_id': tool_id,
         }
         metadata1_origin = {
             'origin_id': self.origin_id_1,
             'metadata': metadata1,
+            'mappings': [],
             'indexer_configuration_id': tool_id,
             'from_revision': self.revision_id_1,
         }
@@ -1679,11 +1704,13 @@
         metadata2_rev = {
             'id': self.revision_id_2,
             'translated_metadata': metadata2,
+            'mappings': [],
             'indexer_configuration_id': tool_id,
         }
         metadata2_origin = {
             'origin_id': self.origin_id_2,
             'metadata': metadata2,
+            'mappings': [],
             'indexer_configuration_id': tool_id,
             'from_revision': self.revision_id_2,
         }
diff --git a/swh/indexer/tests/test_metadata.py b/swh/indexer/tests/test_metadata.py
--- a/swh/indexer/tests/test_metadata.py
+++ b/swh/indexer/tests/test_metadata.py
@@ -254,7 +254,7 @@
                 'name': 'test_metadata',
                 'version': '0.0.1'
             },
-            'id': hash_to_bytes('26a9f72a7c87cc9205725cfd879f514ff4f3d8d5')
+            'id': hash_to_bytes('26a9f72a7c87cc9205725cfd879f514ff4f3d8d5'),
             }, {
             'translated_metadata': {
                 '@context': 'https://doi.org/10.5063/schema/codemeta-2.0',
@@ -927,6 +927,7 @@
                 'name': 'yarn-parser',
                 'keywords': ['yarn', 'parse', 'lock', 'dependencies'],
             },
+            'mappings': ['npm'],
         }]
 
         for result in results:
diff --git a/swh/indexer/tests/test_origin_metadata.py b/swh/indexer/tests/test_origin_metadata.py
--- a/swh/indexer/tests/test_origin_metadata.py
+++ b/swh/indexer/tests/test_origin_metadata.py
@@ -94,11 +94,13 @@
     rev_metadata = {
         'id': rev_id,
         'translated_metadata': metadata,
+        'mappings': ['npm'],
     }
     origin_metadata = {
         'origin_id': origin['id'],
         'from_revision': rev_id,
         'metadata': metadata,
+        'mappings': ['npm'],
     }
 
     results = list(indexer.idx_storage.revision_metadata_get([rev_id]))